In a great majority of large grocery stores or supermarkets, customers select their groceries and then cart them in suitable carriages to a checking-out point where a cashier checks the items purchased and determines the total sale price to be paid by the customer. This method of merchandising has also been extended to other retail stores.
In such systems, conveyor belt means are frequently employed to feed a succession of items to be checked from an unloading position to a sacking position. In such arrangement, the customer unloads the items on a loading platform at the loading position and places them on the conveyor belt means, which leads them to a checking position where items are checked by the cashier. The items are then conveyed by another conveyor belt means to a sacking platform, where the sacker places the items in suitable bags or other containers.
It should be understood that the invention is applicable to material handling systems of various kinds; however, the preferred application of the invention is, as stated above, in connection with automated check-out systems in retail stores, particularly grocery stores or supermarkets; and it will hereinafter be described as applied to such systems. Also, the conveying means are preferably in the form of conveyor belts; but the invention is generally applicable to other various types of conveying apparatus.
Commonly, in systems under discussion, a sensing device is provided at the delivery end of the incoming conveyor belt, that is, at the end of the moving belt adjacent the check-out or cashier stand. The sensing device responds to the breaking of a light beam by the product or item first in line arriving at that end to automatically stop the moving operating belt. As the cashier lifts the product from the belt to check it out, the light beam again strikes the scanning device; and, as a result, the conveyor belt is restarted. This cycle repeats itself as the item next in line reaches this end of the conveyor belt.
When the number of items on the conveyor belt leading to the check-out system is light or becomes non-existent, that is, when no further items are being placed on the belt by waiting customers, the belt keeps running since the sensing device ceases to detect arriving products. As a consequence, there is unnecessary wear and tear on the belt and its driving equipment; and this is accompanied by a corresponding waste of energy.
U.S. Pat. No. 4,236,604 (which is incorporated herein by reference) discloses a sensing device, positioned at the delivery end of the conveying means, as a control for stopping the conveying means in response to the detection of an item by the sensing device; the patent also discloses a time control for automatically stopping the conveying means in response to the sensing device not detecting an item within a predetermined time interval. As shown in U.S. Pat. No. 4,236,604, the checked-out products are frequently packaged at a station separate from the check-out stand proper; and, in such cases, the checked-out products are transported from the check-out station to the packaging station by an additional outgoing conveying means. The aforementioned time control is arranged to stop both the incoming and outgoing conveying means responsive to no item being detected within a predetermined time by the sensing device at the delivery end of the incoming conveying means. By thus automatically also shutting down the outgoing conveyor at times when there is no demand, the wear and tear of this outgoing conveyor and its associated equipment is likewise reduced; and, importantly, the attendant waste of energy and operating expense is obviated.